The present invention relates to fluid control valves and more particularly to a fluid control valve which is less susceptible to the effect of noise.
In the art of linear solenoid control valves, it has been the known practice to detect the actual position of a movable valve element by a differential transformer and feed the detected position signal back to an electric driving circuit of the control valve thereby improving the control accuracy.
In the past, generally such driving circuit has been mounted in a control panel installed at a remote place from a fluid control valve and the connection between the driving circuit and a solenoid actuator of the fluid control valve is provided by laying long electric wires.
As a result, a driving circuit mounting space must be provided in the control panel thus causing a problem from the standpoint of decreasing the size of the control panel and the wiring operation requires much time and labor since it is necessary to lay as the connection wires several kinds of electric wires including a pair of actuator driving wires, a pair of feedback wires, a pair of differential transformer operating wires, etc. Also, if the wires are increased in length, external noise tends to enter the connection wires of the differential transformer and this tends to cause erroneous operations.